Surgical knife



(No Model.)

M. SOHOTT. SURGICAL KNIFE.

NO. 431,153. Patented. July 1,1890.

Waim 6:5 Zn/myth],

m: NORRIS PETERS c0, mmc-umu., vusumamu, a. c

UNITED STATES PATENT OFFICE.

MATHILDE SCHOTT, OF NEWV HAVEN, CONNECTICUT.

SURGICAL KNIFE.

SPECIFICATION forming part of Letters Patent No. 431,153, dated July 1, 1890.

ApplicatioufiledApn'l23,1890. Serial amateur. (Model) To ctZZ whom it may concern:

Be it known that I, MATHILDE SOHOTT, a citizen of the United States, residing in New Haven, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Surgical Instruments, of which the following is a specification, reference being had to the accompanying drawings, forming a part of'the same.

This invention relates to knives, surgical and dental instruments, and tools of various kinds whose'blades or operative parts are detachably secured in theirhandles, wherebya single handle can be made to answer for a number of different blades or other operative parts of instruments or tools. Itis, however, especially designed and adapted for surgical and dental instruments. Many means have heretofore been devised for detachably uniting such instruments to their handles, but most of them have been too expensive and complicated in their construction, and have failed to attach the parts in such manner that they were immovable relatively to each other, which is a very desirable requisite in most surgical and dental instruments. In view of the recent discoveries and advances in the use of antiseptic preparations in surgical operations, whereby, among other precautions, the instruments employed are kept immersed in such preparations except when in actual use, and the handles of such instruments are also subjected to frequent disinfecting and antiseptic treaiment, including boiling in hot water, it is considered of prime importance that the construction of such instruments should be the plainest and simplest possible-that is, that they should be free from sharp angles, notches, narrow ways and roughened surfaces which are diflicult to be readily reached and perfectly cleaned.

To this end it is the object of my invention to provide a plain and simple construction, both of the shank of the instrument and the socket of the handle into which the shank is inserted and secured, and at the same time to provide a simple device for securing the instrument immovably in its handle, but in such manner that it can be instantaneously removed and another substituted,

In the accompanying drawings, Figure 1 is a side view of a surgeons knife containing tion to show the socket.

my invention. Fig. 2 is the same view, the end of the handle being sectioned to show the shank of the blade. Fig. 3 isau edge View of the handle, the end next the blade being in sec- Fig. 4 is a cross-section through the line as a: of Fig. 3, and Fig. 5 is adetail view of the screw and lever arm or handle.

In the drawings, A represents the blade, and B the handle, of a surgeons knife. The blade is furnished with a plain smooth solid shank C, which is inserted in a correspondingly-shaped plain smooth socket D, formed in the end of the handle. The shank and the socket should be of such relative size and shape as to give as accurate a fit as practicable when the shank is inserted in place-that is, the edges of the shank should be in contact with the edge walls of the socket, and the thickness of the socket should only be sufficient to permit of the easy entrance of the shank. Y

E is a screw threaded through one of the side walls of the socket D about the center of the width of the handle 13 near its end, and is provided with a lever or crank arm F, which lies backward along and in contact with the surface of the handle when the blade is. fastened in place. One-eighth of a forward turn of this lever-arm is sufficient to fasten the blade immovably in its socket, and the same backward turn will release the blade and permit it to be withdrawn and another blade with the same thickness of shank to be inserted. The free end of the arm F is preferably enlarged next the surface of the handle B, so that as the lever is turned forward across the handle this enlargement I will be brought in contact with the handle, and when the arm has reached the extent of its forward movement the frictional contact of the enlargement I with the surface of the handle will hold it or assist to hold it in place.

As an additional means of holding the arm F in position when the blade is secured in place, I prefer to form a shallow cavity or depression in the center of the width of the handle B, whose walls are designated in Fig. 4 of the drawings by the letters Grand II. By making the arm F of spring material this cavity can be made sufficiently deep not only to prevent any liability of the accidental backward movement of the arm I, but also largely to prevent the end of this arm from interfering with the fingers of the operator. This cavity need extend along the handle 13 only slightly beyond the end of the arm F. Then the blade is secured in place in the handle and the arm F lies in the cavity, the force required to cause this arm in turning backward to mount the incline G is only slightly greater than would be required if it Were in contact with the level surface of the handle.

J is a projection to prevent the screw E from being turned too far backward.

It is observed that the construction above described and shown in the drawings is exceedingly plain, simple, and economical, that the blade or other instrument is secured in its handle more firmly and immovably than by any construction Within my knowledge, but in such manner that it can be easily and instantaneously removed and another substituted, and that the construction and combination of parts are almost perfectly adapted to meet the prevailing requirements of antiseptic use.

What is claimed as neW is 1. As a device for detachably securing a blade or other instrument in its handle, a screw provided with a lever or arm having upon its free end an enlargement I, in combination with the surface of a handle, substantially as and for the purpose described.

2. The combination of a lover or arm of a screw for detachably securing a blade or other instrument in its handle, With a cavity or depression formed in the surface of the handle, substantially as and for the purpose set forth.

MATHILDE SOHOTT. Witnesses:

JULIUs TWIss, EDWIN C. DOW. 

